Question

1) A car is moving at 100 km/hr. Its mass is 950 kg. Find its KE.

2) What force is needed to accelerate a 1300-kg car from rest to 20 m/s in 80 m?

3) A 1200-kg car going 30 m/s skids to rest. The friction force is 6000 N. How far does it skid?

Answer 1

1) KE = 1/2 mv^2 = (1/2)(950)(100^2) kg-km^2/hr^2
Not the usual units, but you can do the conversion.

2) 1300 √(20^2/160)

3) a = F/m = 6000/1200 = 5
So, it takes 30/5 = 6 seconds to stop.
s = 30t - 5/2 t^2 where t=6

Answer 2

PHYSICS